The exemplary embodiment relates to a swarf cutter and to a method of cutting swarf. It finds particular application in conjunction with the machining of extruded raw tubes for forming photoreceptor drums and will be described with particular reference thereto. However, it is to be appreciated that the swarf cutter finds application in a variety of machining operations.
Photoreceptor drums for imaging devices, such as printers and copiers, are typically formed from tubes which are extruded from aluminum or similar metal. The extruded tubes or blanks generally have imperfect dimensions and are machined to meet the high tolerance requirements of precision devices. Machining may involve removal of material from the inside surface of the ends of the drum to facilitate precise positioning of end caps, cutting of the ends of the drums to achieve the desired drum length, and lathing the outside surface of the drum to ensure roundness, avoid conicity and form a mirror finish.
To produce a smooth finish suitable for use in an imaging device, the tube is typically subjected to a two-stage lathing operation. In the first stage, referred to as the precut, a relatively thick layer is removed from the surface of the tube with artificial diamond tooling. The tube is rotated while the tool bit is moved parallel with the axis of rotation. This generates a helical strip of material, often referred to as swarf, which may be approximately 0.2 mm in thickness and up to about 200-400 m in length, depending on the diameter and length of the tube. The swarf from the precut is difficult to handle because of its large volume and sharp edges. Additionally, if the swarf breaks while lathing, there is a tendency for defects to form in the workpiece, which are not readily removed in the second stage. Automated vacuum systems are generally unsuited to handling the weight of the swarf from the precut stage so the swarf is often collected in a bin at the back of the lathe and handled manually. This is a labor intensive operation and has to be performed carefully to avoid injuries from the rough cut swarf. In a second stage, referred to as the finish cut, a thin layer, about 0.02 mm in thickness, is removed from the machined tool using natural diamond tooling.